Magnetic coupling is one of the few physical phenomena capable of transmitting actuation forces across a physical barrier. In medicine, remote magnetic manipulation has the potential to make surgery less invasive by allowing untethered miniature devices to enter the body through natural orifices or tiny incisions and then maneuver with minimum disruption to healthy tissue. Magnetic coupling between a permanent magnet embed onboard the medical device and an external magnetic field source allows the medical device to be moved within the body of a patient.
One type of insertable medical device that utilizes magnetic coupling for locomotion is a magnetic capsule used for controlled endoscopy or for site-specific drug delivery. These capsules are inserted into the body of a patient and an external magnetic field is applied to move the magnetic capsule through the body.